Backward DVCS on the pion in Sullivan processes

TL;DR

This paper investigates the feasibility of measuring backward deeply virtual Compton scattering on the pion via Sullivan processes using collinear QCD factorization and pion-to-photon TDAs, aiming to estimate cross-sections for future colliders.

Contribution

It develops a model for pion-to-photon TDAs based on light-front wave functions to facilitate feasibility studies of backward DVCS on the pion.

Findings

Estimates of cross-sections for future electron-ion colliders.

Comparison with forward Sullivan DVCS case.

Model for photon light-front wave functions.

Abstract

The purpose of this work is to do a systematic feasibility study of measuring in backward region deeply virtual Compton scattering on the pion in Sullivan processes in the framework of collinear QCD factorization where pion to photon transition distribution amplitudes (TDAs) describe the photon content of the $\pi$ meson. Our approach employs TDAs based on the overlap of light front wave functions, using a previously developed pion light-front wave function and deriving a consistent model for the light front wave functions of the photon. This work is expected to lead us to an estimate of the cross-sections that could be measured in the future U.S. and China's electron-ion colliders. It will also provide a comparison with the forward Sullivan DVCS case, which gives access to pion GPDs and for which a strong signal is expected.